1). Field of the Invention
This invention relates to a phase adjustment mechanism for a variable transmission.
2). Discussion of Related Art
A transmission system transfers power from a first shaft (or axle) to a second shaft (or axle) and allows for adjustment of the ratio of a rotational speed of the first shaft relative to the second shaft. A standard bicycle has a transmission with two sets of cogs of varying sizes connected by a roller chain. One or more derailleur shift systems move the chain laterally by increments so that cogs of varying relative sizes are connected, varying the ratio that the front driving cog rotates relative to the rear cog that is connected to the rear wheel.
Attempts have been made in the past to design a bicycle transmission that does not have a derailleur. A derailleur is a relatively complex and delicate mechanism that does not allow gear changing while stationary or at slow speeds. U.S. Pat. No. 724,449 describes a transmission having a plurality of supports that form an effective cog and the supports are adjustable relative to one another to vary the size of the effective cog. The system in the U.S. Pat. No. 724,449, however, has a mechanism for adjusting the support members relative to one another, but the mechanism is complex and would be impractical and expensive to make.